Limits on Galactic dark matter with 5 years of EROS SMC data

Afonso, C.; Albert, J. N.; Andersen, J.; Ansari, R.; Aubourg, E.; Bareyre, P.; Beaulieu, J.-P.; Blanc, G.; Charlot, X.; Couchot, F.; Coutures, C.; Tisserand, Patrick

Limits on Galactic dark matter with 5 years of EROS SMC data

Date

2003

Authors

Afonso, C.

Albert, J. N.

Andersen, J.

Ansari, R.

Aubourg, E.

Bareyre, P.

Beaulieu, J.-P.

Blanc, G.

Charlot, X.

Couchot, F.

Publisher

Springer

Abstract

Five years of EROS data towards the Small Magellanic Cloud have been searched for gravitational microlensing events, using a new, more accurate method to assess the impact of stellar blending on the efficiency. Four long-duration candidates have been found which, if they are microlensing events, hint at a non-halo population of lenses. Combined with results from other EROS observation programs, this analysis yields strong limits on the amount of Galactic dark matter made of compact objects. Less than 25% of a standard halo can be composed of objects with a mass between 2 × 10-7 M⊙ and 1 M⊙ at the 95% C.L.